A Pew Research Center study found that more adults leave the Catholic Church than enter it in most countries, but Catholics still make up the majority of the population in a number of countries analyzed.
The research released April 23 found that Christianity has experienced some of the largest losses of followers due to religious switching, when people identify with a different religion in adulthood than they were raised in as a child, compared with other faith groups around the world.
The U.S. data in the report, “Catholicism Has Lost People to Religious Switching in Many Countries, While Protestantism Has Gained in Some,” comes from the Center’s 2023-24 U.S. Religious Landscape Study (RLS). The international data comes from surveys conducted by Pew in spring 2024.
The global data that analyzed 24 countries was from Pew’s international surveys conducted via telephone or face-to-face interviews. Pew has conducted more than 800,000 interviews in over 110 countries. The margin of sampling error is based on individual countries’ research.
Religious switching impact on Catholicism
Religious switching has affected Catholicism and Protestantism, two of the largest Christian subgroups, in differing ways. Catholicism has lost more people than it has gained in almost all the countries surveyed, whereas Protestantism has seen a net gain from religious switching.
Despite losses from religious switching, Catholics still make up the majority of the population in eight of the 24 nations Pew surveyed, including Poland (92%), the Philippines (80%), Italy (69%), Mexico (67%), Peru (67%), Hungary (63%), Colombia (60%), and Argentina (58%).
In 12 of the 24 surveyed countries, most of the population was raised Catholic and many adults still identify with the faith today. For example, 96% of Polish adults were raised Catholics. Of the group, 92% still identify with the religion, with 4% reporting they have left Catholicism.
Hungary also experienced a slight loss with 57% of the population identifying as lifelong Catholics and only 2% reporting that they left the Church.
But overall, more people left Catholicism than joined it in 21 of the countries. People who leave Catholicism tend to join Protestantism or disaffiliate from religion altogether, the report said.
Disaffiliation was found to be especially common in parts of Europe and Latin America, including Chile, where 19% of all adults who are former Catholics identify as atheist, agnostic, or “nothing in particular.”
In comparison, in Kenya, Brazil, Ghana, Nigeria, and the Philippines, former Catholics are more likely to have joined Protestantism than to have become religious “nones,” the report said.
Other adults have left the Church, with former Catholics making up 10% or more of the total population in 15 countries.
In Italy, 22% of adults said they were raised Catholic but no longer identify as such, and an additional 1% were not raised Catholic but entered the Church. The nationʼs Catholic population experienced a net loss of 21% due to religious switching.
In the United States, 30% of adults surveyed reported they were raised Catholic and only 17% remain Catholic. An additional 2% who were not raised Catholic reported they entered the Church, for a total of 19% of U.S. adults who are Catholic.
Impact on other religions
Similar to Catholics, former Protestants also make up a large share of the population in many countries. In nine of the 24 countries analyzed, the group was found to make up 10% or more of the population.
In several countries, more people have joined Protestantism than have left it, with the religion having a net gain from switching in almost as many places as it has seen a net loss. Adults who leave Protestantism tend to become religiously unaffiliated, the report said.
Most of the countries where Protestantism has had net gains are in Latin America, including in Brazil where 15% have joined Protestantism and 6% have left. Most Brazilians who reported switching into Protestantism were former Catholics.